JP7222723B2 - Display device - Google Patents

Description

The present invention relates to display devices.

2. Description of the Related Art In recent years, display devices using a liquid crystal display panel, an organic EL display panel, or the like have become common. In such a display device, an image is displayed by reading one line of image data into a buffer memory and outputting the image data in the buffer memory to the display panel in accordance with a timing signal (at a constant cycle). For example, there has been disclosed a display device that suppresses flickering of image display even if the capacity of the buffer memory is small and an underrun occurs (see, for example, Patent Document 1).

JP 2016-218833 A

In portable terminal devices such as smartphones and tablet PCs and stationary PCs, an OS (Operating System) that provides a UI (User Interface) environment and a plurality of applications that run on the OS are installed in a storage device. Predetermined functions are realized by operating the OS and each application in cooperation with each other. The timing of image display on the display panel is determined by the specifications of the OS, application, or web page accessed using a web browser. Situations can arise that can make a big difference. Such unnatural transition of image display may be recognized as flickering of image display. In addition, there is a possibility of impeding the user's vision, mind and body.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display device capable of suppressing flicker in image display due to abrupt changes in image data.

A display device according to an aspect of the present invention includes a first memory storing first image data including a plurality of first pixel data and a second memory storing second image data including a plurality of second pixel data. a memory; an averaging processor that averages the pixel values of the first pixel data and the pixel values of the second pixel data for each frame; and a display unit for displaying an image based on the pixel value of the first pixel data of the n-th frame stored in the first memory, and the pixel value of the first pixel data stored in the second memory. and the pixel value of the second pixel data after the averaging process of the (n−1)th frame, and the pixel value after the averaging process is used as the pixel value of the second pixel data of the nth frame. Output as data and write back to the second memory.

FIG. 1 is a schematic diagram showing a schematic configuration of a display device according to Embodiment 1. FIG. FIG. 2 is a block diagram illustrating a configuration example of a main part of the display device according to the first embodiment; FIG. 3 is a diagram illustrating an example of display mode transition of the display device according to the first embodiment. 4 is a diagram illustrating an example of a data table stored in a storage unit of the display device according to the first embodiment; FIG. FIG. 5 is a diagram showing the relationship between the pixel value _Yn of the first pixel data of the n-th frame and the pixel value _Xn of the second pixel data of the n-th frame. 6 is a diagram illustrating an example of averaging processing of the display device according to the modification of the first embodiment; FIG. FIG. 7 is a block diagram illustrating a configuration example of a main part of a display device according to a second embodiment; 8 is a first diagram showing an example of a data table stored in a storage unit of the display device according to the second embodiment; FIG. FIG. 9 is a first diagram showing changes in the weighting factor α of the display device according to the second embodiment. 10 is a second diagram showing an example of a data table stored in a storage unit of the display device according to the second embodiment; FIG. FIG. 11 is a second diagram showing changes in the weighting factor α of the display device according to the second embodiment. 12 is a first diagram showing an example of a data table stored in a storage unit of a display device according to a modification of the second embodiment; FIG. FIG. 13 is a first diagram showing changes in the weighting factor α of the display device according to the modification of the second embodiment. 14 is a second diagram illustrating an example of a data table stored in a storage unit of the display device according to the modification of the second embodiment; FIG. FIG. 15 is a second diagram showing changes in the weighting factor α of the display device according to the modification of the second embodiment. FIG. 16 is a block diagram illustrating a configuration example of a main part of a display device according to a third embodiment; 17A and 17B are diagrams illustrating an example of display mode transition of the display device according to the third embodiment. 18 is a flowchart illustrating an example of display mode switching processing of the display device according to the third embodiment; FIG. FIG. 19 is a block diagram illustrating a configuration example of a main part of a display device according to a fourth embodiment; FIG. 20 is a diagram illustrating an example of display mode transition of the display device according to the fourth embodiment. FIG. 21 is a flowchart illustrating an example of display mode switching processing of the display device according to the fourth embodiment.

A form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. In addition, the present invention is not limited by the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the components described below can be combined as appropriate. Further, the disclosure is merely an example, and those skilled in the art are naturally included in the scope of the present invention for appropriate modifications that can be easily conceived while maintaining the gist of the invention. In addition, in order to make the description clearer, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the actual embodiment, but this is only an example, and the interpretation of the present invention is not intended. It is not limited. In addition, in this specification and each figure, the same reference numerals may be given to the same elements as those described above with respect to the existing figures, and detailed description thereof may be omitted as appropriate.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a schematic configuration of a display device according to Embodiment 1. FIG. As shown in FIG. 1, the display device 1 according to this embodiment includes a display substrate 2, a first circuit substrate 3, and a second circuit substrate 4. As shown in FIG.

In this embodiment, the display substrate 2 is composed of, for example, a glass substrate. The display substrate 2 is provided with a display section 10 in which pixels (not shown) are arranged in the X direction and the Y direction in the figure.

The display unit 10 may have a configuration including a liquid crystal display element as a display element, for example. Further, the display unit 10 may be, for example, an organic EL display panel (OLED: Organic Light Emitting Diode) or an inorganic EL display (micro LED, Mini-LED) using light emitting elements as display elements.

Further, the display unit 10 may be a so-called in-cell type or hybrid type device in which a capacitive touch sensor is integrated, for example. Integrating a capacitive touch sensor into the display unit 10 means, for example, part of the display substrate and electrodes and part of the substrate and electrodes used as the touch sensor. It includes also serving as a member. Alternatively, the display unit 10 may be a so-called on-cell type device equipped with a capacitive touch sensor, for example. The present disclosure is not limited by the aspect of the display unit 10 .

The display substrate 2 is provided with scanning signal lines that supply scanning signals to the pixel circuits of the display section 10 and video signal lines that supply video signals to the pixel circuits of the display section 10 .

In this embodiment, the first circuit board 3 is configured by, for example, a flexible printed circuit board (FPC: Flexible Printed Circuits). A driver IC 6 and a timing controller 7 are mounted on the first circuit board 3 .

The driver IC 6 is, for example, a semiconductor chip in which a video line driving circuit that supplies video signals to the video signal lines of the display section 10, a scanning signal line driving circuit that supplies scanning signals to the scanning signal lines of the display section 10, and the like are integrated. is.

The timing controller 7 is, for example, a semiconductor chip in which a line memory, a multiplexer, a timing pulse supply section, etc. are integrated. The timing controller 7 controls the driver IC 6 based on image data, a horizontal synchronizing signal, a vertical synchronizing signal, a clock signal, etc. input from the host IC 8, which will be described later.

The driver IC 6 and the timing controller 7 are mounted on the first circuit board 3 by COF (Chip On Film) using, for example, an anisotropic conductive film (ACF) (hereinafter referred to as "COF mounting"). . The driver IC 6 and the timing controller 7 may be composed of separate semiconductor chips, or may be composed of one semiconductor chip. A semiconductor chip having the driver IC 6 , the timing controller 7 and the like may be mounted on the display substrate 2 .

In this embodiment, the second circuit board 4 may be configured by, for example, a flexible wiring board, or may be configured by a rigid circuit board. Circuit elements such as a host IC 8 that controls the timing controller 7, a power supply circuit that generates various reference potentials, a signal processing circuit that processes video signals, and a frame memory can be arranged on the second circuit board 4. can. The host IC 8 is a component that controls the operation of the display device 1 by the user's operation of the user input section 9 . The user input unit 9 may be, for example, a touch sensor provided on the display unit 10 or hardware buttons (not shown) provided on the display device 1 .

FIG. 2 is a block diagram illustrating a configuration example of a main part of the display device according to the first embodiment; The image data processing unit 20 shown in FIG. 2 and the control unit 30 that controls the operation of the image data processing unit 20 are provided in the driver IC 6 or the timing controller 7, for example. The image data processing unit 20 and the control unit 30 may be provided separately in the driver IC 6 and the timing controller 7, respectively, or may be provided in either the driver IC 6 or the timing controller 7. good.

In the following description, the image data transmitted and received between the components is a group of pixel data having a predetermined resolution and to be displayed in one frame period of the video signal. In this embodiment, the resolution of image data is assumed to be constant. For example, if the image data has a resolution of 1920×1080 pixels, the image data includes 1920×1080 pixel data.

In this embodiment, the display unit 10 displays an image based on image data output from the image data processing unit 20 at a predetermined frame rate (eg, 60 [Hz]).

FIG. 3 is a diagram illustrating an example of display mode transition of the display device according to the first embodiment. As shown in FIG. 3, the display device 1 according to this embodiment has a normal display mode and a time average image display mode as display modes.

In the normal display mode, the image data processing section 20 outputs the first image data input to the image data processing section 20 .

In the time average image display mode, the image data processing unit 20 outputs the second image data after the averaging process according to this embodiment. The averaging process according to this embodiment will be described later.

That is, in the present embodiment, the normal display mode is a display mode in which the first image data input to the image data processing unit 20 is output without being subjected to the averaging process according to the present embodiment. The image display mode is a display mode in which the first image data input to the image data processing unit 20 is subjected to the averaging process according to the present embodiment and the second image data is output.

As shown in FIG. 2, the image data processing unit 20 includes a first memory 21, a second memory 22, an averaging processing unit 23, a buffer memory 24, an image data selection unit 25, a storage unit 26, and a data input unit 27 .

The data input unit 27 includes a frame thinning processing unit 271 that performs frame thinning processing of the input first image data in the time average image display mode. By this frame thinning processing, it is possible to suppress the amount of calculation required for the averaging processing by the averaging processing section 23 in the subsequent stage. Note that the frame thinning processing unit 271 does not perform frame thinning processing of the input first image data in the normal display mode.

The first memory 21 and the second memory 22 are, for example, VRAMs such as DRAMs.

The first memory 21 stores the first pixel data for one frame of the input first image data. The first memory 21 also outputs the stored first pixel data to the averaging processor 23 and the image data selector 25 . Hereinafter, let the pixel value of each first pixel data stored in the first memory 21 be Y _n (n indicates the pixel value of the n-th frame). In this embodiment, the pixel value indicates the gradation value of image data for each pixel. The gradation value of image data is a value corresponding to the brightness of each pixel.

The second memory 22 stores pixel data for one frame after the averaging processing by the averaging processing section 23 as second image data. The second memory 22 also outputs each stored second pixel data to the averaging processing section 23 . Hereinafter, the pixel value of each second pixel data stored in the second memory 22 after the averaging processing by the averaging processing unit 23 is assumed to be _Xn .

The averaging processing unit 23 reads out the first pixel data stored in the first memory 21 and the second pixel data stored in the second memory 21 line by line. An averaging process is performed on the pixel value _Yn and the pixel value Xn _-1 of the second pixel data. Further, the averaging processing unit 23 writes the pixel value _Xn after the averaging processing back to the second memory 22 and outputs it to the buffer memory 24 in the subsequent stage.

The buffer memory 24 stores the pixel value _Xn of each second pixel data for one line output from the averaging processing section 23 and outputs it to the image data selection section 25 .

The image data selection unit 25 selects and outputs either the first image data input from the first memory 21 or the second image data input from the buffer memory 24 . Specifically, the image data selection unit 25 selects the first image data in the normal display mode, and selects the second image data in the time average image display mode.

Information for averaging processing by the averaging processing unit 23 is stored in the storage unit 26 .

Next, operation in each display mode and switching between display modes will be described. Note that switching between display modes shown in FIG. 3 is performed by the control unit 30 .

Specifically, for example, when the user operates the user input unit 9 to select "ON" of the time average image display mode, the control unit 30 performs display in the time average image display mode. , controls the image data processing unit 20 .

Further, for example, when the user operates the user input unit 9 to select "OFF" of the time average image display mode, the control unit 30 causes the image data processing unit to perform display in the normal display mode. 20.

When the user input unit 9 is a hardware button, the user may switch the display mode according to the number of times the hardware button is pressed or the elapsed time. Further, when the user input unit 9 is a touch sensor, the display mode may be switched by the user according to a touch operation on an icon displayed on the display unit 10 or a predetermined gesture. The present invention is not limited by the display mode switching method by the user.

In the normal display mode, the control section 30 outputs a normal display operation command to the image data processing section 20 .

The frame thinning processing unit 271 stops the frame thinning processing of the input first image data based on the normal display operation command.

The averaging processing unit 23 stops the averaging processing based on the normal display operation command.

The image data selection unit 25 selects and outputs the first image data output from the first memory 21 based on the normal display operation command.

As a result, the first image data input to the image data processing unit 20 is output, and the image is displayed in the normal display mode.

In the time average image display mode, the control unit 30 outputs a time average image display operation command to the image data processing unit 20 .

The frame thinning processing unit 271 performs frame thinning processing of the input first image data based on the time average image display operation command. Specifically, for example, the frame thinning process is performed so that the frame rate (eg, 40 [Hz]) is lower than the frame rate (eg, 60 [Hz]) at which an image is displayed by the display unit 10. . As a result, it is possible to suppress the amount of calculation required for the averaging processing by the averaging processing unit 23 in the subsequent stage. It is preferable that the frame rate after the frame thinning process is asynchronous with the frame rate when the display unit 10 performs image display. This diffuses the tearing lines. This frame thinning process may be a mode in which the user can select whether or not to perform the frame thinning process by operating the user input unit 9 .

The averaging processing unit 23 performs averaging processing based on the time average image display operation command.

The image data selection unit 25 selects and outputs the second image data output from the buffer memory 24 based on the time average image display operation command.

As a result, the second image data after the averaging processing by the averaging processing unit 23 is output, and the image is displayed in the time average image display mode.

The averaging process will be described below.

For example, the pixel value _Xn of the second pixel data of the n-th frame can be calculated by weighted average processing using the following formula (1).

X _n = {αX _n−1 ^β + (1−α) Y _n ^β } ^(1/β) (1)

In the above equation (1), α is a weighting factor for averaging. A plurality of values are set for the weighting factor α within the range of 0≦α<1. For example, 20 values may be set with a predetermined step size of 1/20.

Also, in the above equation (1), β is, for example, a gamma value in gamma correction. This gamma value may be, for example, 2.2, or may be a different value. Also, the value of β may be set externally by register setting or the like.

By appropriately setting the weighting factor α in the above equation (1), the second image data in which the steep fluctuation of the first image data is suppressed can be obtained, and the flickering of the image display can be suppressed.

Note that the above equation (1) includes exponential processing, so the amount of calculation required for the averaging processing increases. For this reason, in the present embodiment, the averaging processing unit 23 uses the following equations (2) and (3), which are linear approximations of the above equation (1), to calculate the pixel value of the second pixel data of the n-th frame. Calculate _Xn . Specifically, the averaging processing unit 23 determines that the pixel value Xn _-1 of the second pixel data of the n-1th frame is equal to or greater than the pixel value _Yn of the first pixel data of the nth frame ( _Xn-1 ≧Yn), the pixel value X n of the n-th frame second pixel data is calculated using the following equation (2), and the pixel value X _n of the (n−1)-th frame second pixel data is calculated. When _n-1 is less than the pixel value Y _n of the first pixel data of the n-th frame (X _n-1 <Y _n ), the second pixel of the n-th frame is calculated using the following equation (3) A pixel value X _n of the data is calculated.

X _n = α ^(1/β) X _n-1 + {1-α ^(1/β) } Y _n (2)

X _n = {1-(1-α) ^(1/β) } X _n-1 + (1-α) ^(1/β) Y _n (3)

where A=α ^(1/β) , B=1−α ^(1/β) , C=1−(1−α) ^(1/β) , D=(1−α) ^(1/β) Then, the above formulas (2) and (3) can be generalized to the following formulas (2') and (3').

X _n =AX _n−1 +BY _n (2′)

_Xn = CXn _-1 + _DYn (3')

4 is a diagram illustrating an example of a data table stored in a storage unit of the display device according to the first embodiment; FIG. In the example shown in FIG. 4, the step width of the weighting factor α is 1/m (m is an integer equal to or greater than 1).

As shown in FIG. 4, each coefficient value ( A, B, C, D) are stored as a data table.

Specifically, in the example shown in FIG. 4, the storage unit 26 stores coefficient values (A1, B1, C1, D1) corresponding to the value "a1" of the weighting coefficient α.

In the example shown in FIG. 4, the storage unit 26 stores coefficient values (A2, B2, C2, D2) corresponding to the value "a2" of the weighting coefficient α.

Further, in the example shown in FIG. 4, the storage unit 26 stores coefficient values (A3, B3, C3, D3) corresponding to the value "a3" of the weighting coefficient α.

In the example shown in FIG. 4, the storage unit 26 stores each coefficient value (Am, Bm, Cm, Dm) corresponding to the value "am" of the weighting coefficient α.

The averaging processing unit 23 reads the coefficient values of the terms of the above equations (2′) and (3′) from the data table shown in FIG. The pixel value _Xn is calculated using the equation (3').

This makes it possible to suppress flicker in image display while suppressing the amount of calculation required for the averaging processing by the averaging processing unit 23 .

FIG. 5 is a diagram showing the relationship between the pixel value _Yn of the first pixel data and the pixel value _Xn of the second pixel data. In the example shown in FIG. 5, the horizontal axis indicates frames, and the vertical axis indicates pixel values. Also, in the example shown in FIG. 5, the broken line indicates the pixel value _Yn of the first pixel data, and the solid line indicates the pixel value _Xn of the second pixel data.

In the present embodiment, as shown in FIG. 5, the pixel value _Xn of the second pixel data after the averaging processing by the averaging processing unit 23 is the pixel value _Yn of the first pixel data. Abrupt changes are suppressed. As described above, in the present embodiment, in the time average image display mode, the averaging processing by the averaging processing unit 23 realizes image display based on the second image data in which flickering caused by a steep change in the first image data is suppressed. be able to.

Further, in the present embodiment, the above equation (1) or the above equations (2) and (3) taking into account the gamma value in the gamma correction is used to calculate the first n-th frame input from the first memory 21. By averaging the pixel value _Yn of the pixel data and the pixel value Xn- ₁ of the second pixel data of the n-1th frame input from the second memory 22, the brightness of the intermediate tone is lowered. can be suppressed.

Further, for example, when the pixel value _Yn of the first pixel data for one line and the pixel value Xn _-1 of the second pixel data for one line match in the averaging processing unit 23, one line A mode in which the minute averaging process is not performed is also possible. In this case, the averaging unit 23 calculates the pixels of the first pixel data for one line where the pixel value _Yn of the first pixel data and the pixel value Xn _-1 of the second pixel data match. Output the value Y _n . By doing so, it is possible to further reduce the amount of calculation required for the averaging process.

(Modification)
6 is a diagram illustrating an example of averaging processing of the display device according to the modification of the first embodiment; FIG. FIG. 6 shows an example in which the pixel value Xn _{-1 of the second pixel data of the n-1th} frame and the pixel value _Yn of the first pixel data of the nth frame are each 8-bit digital values. .

In the modification of the first embodiment, the pixel value _Xn of the second pixel data of the nth frame is the upper 4 bits of the pixel value Xn−1 of the second pixel data of the n−1th frame and the pixel value _Xn−1 of the second pixel data of the nth frame. Averaging processing is performed using the upper 4 bits of the pixel value Y _n of the first pixel data, and the remaining lower 4 bits of the pixel value Y _n of the first pixel data of the nth frame are applied to the remaining lower 4 bits. do.

As shown in FIG. 6, the pixel value _Xn-1 of the second pixel data of the n-1th frame and the pixel value _Yn of the first pixel data of the nth frame are obtained by the following equation (4) and It can be expressed by the following formula (5).

X _n−1 =X _n−1 _upper+X _n−1 _under (4)

_Yn = _{Yn_upper} + _{Yn_under} (5)

In the above equation (4), X _n−1 _upper represents the upper 4 bits of the pixel value X n− ₁ of the second pixel data of the n−1th frame, and X _n−1 _under represents the n−1th frame. shows the lower 4 bits of the pixel value Xn _-1 of the second pixel data. In the above equation (5), _{Yn_upper} indicates the upper ₄ bits of the pixel value Yn of the first pixel data of the nth frame, and _{Yn_under} is the pixel of the first pixel data of the nth frame. It shows the lower 4 bits of the value _Yn .

By applying the above formulas (4) and (5) to the above formulas (2) and (3), the following formulas (6) and (7) are obtained.

_Xn
=α ^(1/β) (X _n−1 _upper+X _n−1 _under)
+ {1−α ^(1/β) }(Y _n _upper+Y _n _under)
=[α ^(1/β) (X _n−1 _upper)+{1−α ^(1/β) }(Y _n _upper)]
+[α ^(1/β) (X _n−1 _under)+{1−α ^(1/β) }(Y _n _under)]
... (6)

_Xn
= {1−(1−α) ^(1/β) }(X _n−1 _upper+X _n−1 _under)
+(1−α) ^(1/β) ( _{Yn_upper} + _{Yn_under} )
= [{1-(1-α) ^(1/β) }(X _n-1 _upper)
+(1−α) ^(1/β) (Y _n _upper)}]
+ [{1−(1−α) ^(1/β) }(X _n−1 _under)
+(1−α) ^(1/β) (Y _n _under)}] (7)

where A=α ^(1/β) , B=1−α ^(1/β) , C=1−(1−α) ^(1/β) , D=(1−α) ^(1/β) Then, the above formulas (6) and (7) can be generalized to the following formulas (6′) and (7′).

_Xn = {A(Xn _{-1_upper} ) + B( _{Yn_upper} )}
+{A(X _n−1 _under)+B(Y _n _under)} (6′)

_Xn = {C(Xn _{-1_upper} )+D( _{Yn_upper} )}
+{C(X _n−1 _under)+D(Y _n _under)} (7′)

On the other hand, assuming that the pixel value _Yn of the n-th frame is equal to the pixel value _Ym of the m-th frame after the n-th frame ( _Ym = _Yn ), the second pixel data of the i-th frame can be expressed by the following _equation (8).

X _i (i→∞)=Y _i _upper+Y _i _under=Y _n (8)

That is, in the transition period, the pixel value X _i (i→∞) of the second pixel data of the i-th frame converges to the pixel value Y _n of the first pixel data of the n-th frame. From this, the above formulas (6') and (7') can be expressed by the following formulas (9) and (10), respectively.

_Xn ≈ {A(Xn _{-1_upper} ) + B( _{Yn_upper} )} + _{Yn_under}
... (9)

_Xn≈ {C(Xn _{-1_upper} )+D( _{Yn_upper} )}]+ _{Yn_under}
(10)

The following equation (11) is obtained by replacing { } in the above equations (9) and (10) with "Ave{X _n−1 _upper+Y _n _upper}".

X _n ≈Ave {X _n−1 _upper+Y _n _upper}+Y _n _under
(11)

That is, as shown in FIG. 6, the pixel value _Xn of the second pixel data of the n-th frame is the pixel value Xn- _{1 of the second pixel data of the n-} 1th frame, as described above. Average processing is performed using 4 bits and the upper 4 bits of the pixel value _Yn of the first pixel data of the nth frame, and the remaining lower 4bits are the pixel value _Yn of the first pixel data of the nth frame. Apply the remaining lower 4 bits. As a result, the averaging process using all 8 bits of the pixel value Xn _-1 of the second pixel data of the n-1th frame and the pixel value _Yn of the first pixel data of the nth frame is reduced. , the amount of calculation required for the averaging processing by the averaging processing unit 23 can be suppressed.

It is also possible to adjust the number of bits for averaging according to the accuracy required for the pixel value _Xn of the second pixel data of the n-th frame. For example, an averaging process is performed using the upper 5 bits of the pixel value Xn _-1 of the second pixel data of the n-1th frame and the upper 5bits of the pixel value _Yn of the first pixel data of the nth frame, For the lower 3 bits, the remaining lower 3 bits of the pixel value _Yn of the first pixel data of the nth frame may be applied, or the pixel value X of the second pixel data of the (n−1)th frame may be applied. The upper 6 bits of _n−1 and the upper 6 bits of the pixel value Y _n of the first pixel data of the n-th frame are used to perform averaging processing, and the lower 2 bits are the pixel value of the first pixel data of the n-th frame. It is also possible to apply the remaining lower 2 bits of _Yn .

As described above, the display device 1 according to the first embodiment includes the first memory 21 storing the first image data including the plurality of first pixel data and the second image including the plurality of second pixel data. a second memory 22 for storing data; an averaging processor 23 for averaging the pixel values of the first pixel data and the pixel values of the second pixel data for each frame; and a display unit 10 for displaying an image based on the two image data. The averaging processing unit 23 calculates the pixel value _Yn of the first pixel data of the n-th frame stored in the first memory 21 and the pixel value Yn of the n-th frame after the averaging processing stored in the second memory 22 The pixel value _Xn-1 of the second pixel data is averaged, and the pixel value _Xn after the averaging process is output as the second pixel data of the n-th frame and stored in the second memory 22. write back.

With the above configuration, it is possible to realize image display using the second image data in which flickering due to abrupt changes in the first image data is suppressed.

Further, the averaging processing unit 23 calculates data of a predetermined number of upper bits of the pixel value _Yn of the first pixel data of the n-th frame and the pixel value Xn _-1 of the second pixel data of the n-1th frame. is used to perform averaging processing, and as the data of the number of remaining lower bits of the pixel value X _n of the second pixel data of the n-th frame after the averaging processing, of the first pixel data of the n-th frame The data of the number of remaining low-order bits of the pixel value _Yn are applied.

This makes it possible to reduce the amount of calculation required for the averaging process by the averaging processor 23, compared to the case where the averaging process is performed using all 8 bits of the pixel value Xn _-1 and the pixel value _Yn .

Also, a frame thinning processing unit 271 that performs frame thinning processing of the first image data input to the first memory 21, and an image data selection unit 25 that selects and outputs either the first image data or the second image data. And prepare. The frame thinning processing section 271 performs frame thinning processing when the second image data is selected by the image data selecting section 25 .

As a result, it is possible to suppress the amount of calculation required for the averaging processing by the averaging processing unit 23 in the subsequent stage.

According to the present embodiment, it is possible to obtain the display device 1 capable of displaying an image based on the second image data while suppressing flicker in the image display due to abrupt changes in the first image data.

(Embodiment 2)
FIG. 7 is a block diagram illustrating a configuration example of a main part of a display device according to a second embodiment; It should be noted that duplicate descriptions of components that are equivalent or identical to those of the first embodiment described above will be omitted.

As shown in FIG. 7, the image data processing section 20a of the display device 1a according to the second embodiment includes a luminance difference calculating section 28a in addition to the configuration of the first embodiment.

The luminance difference calculator 28 a calculates the average luminance S[Y _n ] of the pixel value Y _n of the first pixel data included in the first image data of the n-th frame input from the first memory 21 and the second memory 22 . A luminance difference ΔS1 between the average luminance S[X _n−1 ] and the pixel value X _n−1 of the second pixel data included in the second image data of the (n−1)th frame input from .

The luminance difference ΔS1 can be expressed by the following equation (12).

ΔS1=|S[Y _n ]−S[X _n−1 ]| (12)

8 is a first diagram showing an example of a data table stored in a storage unit of the display device according to the second embodiment; FIG. FIG. 9 is a first diagram showing changes in the weighting factor α of the display device according to the second embodiment.

In the example shown in FIG. 8, the storage unit 26a of the present embodiment stores the range of the luminance difference ΔS1 between the average luminance S[Y _n ] and the average luminance S[X _n−1 ] and the value of the weighting factor α “a , "ab"(b<a) are associated, and each coefficient value (A, B, C , D) are stored as a data table.

Specifically, in the example shown in FIG. 8, the value "a" of the weighting factor α when the luminance difference ΔS1 is 0 or more and the first threshold value k or less (0≦ΔS1≦k) is stored in the storage unit 26a. Each coefficient value (A1, B1, C1, D1) is stored corresponding to .

Further, in the example shown in FIG. 8, the storage unit 26a stores the value "ab" (b<a) of the weighting factor α when the luminance difference ΔS1 is greater than the first threshold value k (k<ΔS1). Then, each coefficient value (A2, B2, C2, D2) is stored.

The averaging processor 23a compares the luminance difference ΔS1 calculated by the luminance difference calculator 28a with a predetermined first threshold value k, and as shown in FIG. If it is equal to or less than the threshold k (0≦ΔS1≦k), the weighting factor α is set to the value “a”, and if the luminance difference ΔS1 is greater than the first threshold k (k<ΔS1), the weighting factor α is A value “ab” (b<a) that is smaller than the value “a” is assumed.

Then, the averaging processing unit 23a associates the range of the luminance difference ΔS1 between the average luminance S[Y _n ] and the average luminance S[X _n−1 ] with the value of the weighting factor α, and stores the values in the storage unit 26a. From the data table shown in FIG. 8, the coefficients of the terms of the above formulas (2′) and (3′) corresponding to the range of the luminance difference ΔS1 are read out, and the above formulas (2′) and (3′) are obtained. is used to calculate the pixel value Xn+1.

10 is a second diagram showing an example of a data table stored in a storage unit of the display device according to the second embodiment; FIG. FIG. 11 is a second diagram showing changes in the weighting factor α of the display device according to the second embodiment.

In the example shown in FIG. 10, the storage unit 26a of the present embodiment stores the range of the luminance difference ΔS1 between the average luminance S[Y _n ] and the average luminance S[X _n−1 ] and the value of the weighting factor α “a , "a−b1", "a−b1", "a−b1", and "a−b1" are associated with each other, and the values of the weight coefficient α are "a", "a−b1", and "a−b1". , "a-b1" and "a-b1", each coefficient value (A, B, C, D) is stored as a data table.

Specifically, in the example shown in FIG. 10, the storage unit 26a of the present embodiment stores the weighting factor α when the luminance difference ΔS1 is 0 or more and the first threshold value k1 or less (0≦ΔS1≦k1). Each coefficient value (A1, B1, C1, D1) is stored corresponding to the value "a".

In the example shown in FIG. 10, the storage unit 26a stores the value of the weighting factor α when the luminance difference ΔS1 is greater than the first threshold k1 and equal to or less than the first threshold k2 (k1<ΔS1≦k2). Each coefficient value (A2, B2, C2, D2) is stored corresponding to "a-b1".

In the example shown in FIG. 10, the storage unit 26a stores the value of the weighting factor α when the luminance difference ΔS1 is greater than the first threshold k2 and equal to or less than the first threshold k3 (k2<ΔS1≦k3). Each coefficient value (A3, B3, C3, D3) is stored corresponding to "ab2".

In the example shown in FIG. 10, the storage unit 26a stores the value of the weighting factor α when the luminance difference ΔS1 is greater than the first threshold k3 and equal to or less than the first threshold k4 (k3<ΔS1≦k4). Each coefficient value (A4, B4, C4, D4) is stored corresponding to "a-b3".

Further, in the example shown in FIG. 10, the storage unit 26a stores each factor corresponding to the value "a-b4" of the weighting factor α when the luminance difference ΔS1 is greater than the first threshold value k4 (k4<ΔS1). Numerical values (A5, B5, C5, D5) are stored.

In addition, in the example shown in FIG. 10, the following formula (13) holds.

b1<b2<b3<b4<a (13)

The averaging processor 23a compares the luminance difference ΔS1 calculated by the luminance difference calculator 28a with each of predetermined first thresholds k1, k2, k3, and k4, and as shown in FIG. 9, the luminance difference ΔS1 is If the value is 0 or more and is equal to or less than the first threshold k1 (0≦ΔS1≦k1), the weighting coefficient α is set to the value “a”, and the luminance difference ΔS1 is greater than the first threshold k1 and the first threshold If it is k2 or less (k1<ΔS1≦k2), the weighting factor α is set to the value “a−b1”, and if the luminance difference ΔS1 is greater than the first threshold k2 and is less than or equal to the first threshold k3 ( k2<ΔS1≦k3), the weighting factor α is set to the value “a−b2”, and the luminance difference ΔS1 is greater than the first threshold k3 and equal to or smaller than the first threshold k4 (k3<ΔS1≦k4) , the weighting factor α is set to the value "a−b3", and if the luminance difference ΔS1 is greater than the first threshold value k4 (k4<ΔS1), the weighting factor α is set to the value "a−b4".

Then, the averaging processing unit 23a associates the range of the luminance difference ΔS1 between the average luminance S[Y _n ] and the average luminance S[X _n−1 ] with the value of the weighting factor α, and stores the values in the storage unit 26a. From the data table shown in FIG. 10, the coefficients of the terms of the above formulas (2′) and (3′) corresponding to the range of the luminance difference ΔS1 are read out, and the above formulas (2′) and (3′) are obtained. is used to calculate the pixel value _Xn .

That is, in the present embodiment, as indicated by the dashed lines in FIGS. 9 and 11, the smaller the luminance difference ΔS1 between the average luminance S[Y _n ] and the average luminance S[X _n−1 ], the weighting factor α. increase the value. As a result, when the luminance difference ΔS1 between the average luminance S[Y _n ] and the average luminance S[X _n−1 ] is large, that is, when the luminance difference between the image data of the previous frame and the image data of the next frame is large, Fluctuations in the pixel value _Xn of the image data of the next frame are buffered.

(Modification)
12 is a first diagram showing an example of a data table stored in a storage unit of a display device according to a modification of the second embodiment; FIG. FIG. 13 is a first diagram showing changes in the weighting factor α of the display device according to the modification of the second embodiment.

In the modified example of the second embodiment, among the pixel data for one frame, the pixel data of a specific pixel is set as a sample point, and the second and the pixel value _{Y n} ij of the first pixel data included in the first image data of the n-th frame; When the pixel luminance difference ΔS2 is small, that is, when the matching degree 1/ΔS2 between the pixel value X _n−1 ij of the previous frame and the pixel value Y _n ij of the next frame at the pixel of the sample point is large, the weighting factor α increase the value of In this embodiment, an example in which a plurality of pixels separated by a predetermined number of pixels are used as sample points will be described.

In the modification of Embodiment 2, the luminance difference calculator 28a uses the following equation (14) to calculate the pixel value X _n−1 ij of the second pixel data of the n−1th frame for each pixel serving as a sample point. and the pixel value Y _n ij of the first pixel data of the n-th frame.

ΔS2=Σ|X _n−1 ij−Y _n ij| (14)

In the modification of the second embodiment, as shown in FIG. 12, the storage unit 26a stores the sum of the differences between the pixel value X _n−1 ij and the pixel value Y _n ij at each pixel set as a sample point. The range of the luminance difference ΔS2 is associated with the values “a1” and “a2” of the weighting factor α, and each coefficient value (A, B, C , D) are stored as a data table.

Specifically, in the example shown in FIG. 12, the storage unit 26a stores the weighting coefficient α value “a1 ”, each coefficient value (A1, B1, C1, D1) is stored.

In the example shown in FIG. 12, the storage unit 26a stores the value "a2" (a2<a1) of the weighting factor α when the pixel luminance difference ΔS2 is greater than the first threshold value k (k<ΔS2). , each coefficient value (A2, B2, C2, D2) is stored.

The averaging processor 23a compares the pixel luminance difference ΔS2 calculated by the luminance difference calculator 28a with a predetermined first threshold value k, and as shown in FIG. If it is equal to or less than the first threshold k (0≦ΔS2≦k), the weighting coefficient α is set to the value “a1”, and if the pixel luminance difference ΔS2 is greater than the first threshold k (k<ΔS2), the weight Let the coefficient α be a value “a2” (a2<a1) smaller than the value “a1”.

Then, the averaging processing unit 23a associates the range of the pixel luminance difference ΔS2, which is the sum of the difference between the pixel value Xn ₋₁ and the pixel value _Yn at each pixel set as a sample point, with the value of the weighting factor α. 12 stored in the storage unit 26a, the coefficients of the terms of the above formulas (2') and (3') corresponding to the range of the pixel luminance difference ΔS2 are read out, and the above (2' ) and (3′) are used to calculate the pixel value _Xn .

14 is a second diagram illustrating an example of a data table stored in a storage unit of the display device according to the modification of the second embodiment; FIG. FIG. 15 is a second diagram showing changes in the weighting factor α of the display device according to the modification of the second embodiment.

In the example shown in FIG. 14, the storage unit 26a stores the range of the pixel luminance difference ΔS2, which is the sum of the difference between the pixel value X _n−1 ij and the pixel value Y _n ij at each pixel set as a sample point; The values "a1", "a2", "a3", "a4" and "a5" of the weighting factors α are associated, and the values of the weighting factors α "a1", "a2", "a3", "a4", Corresponding to "a5", each coefficient value (A, B=D, C) is stored as a data table.

Specifically, as shown in FIG. 14, in the modified example of the second embodiment, when the pixel luminance difference ΔS2 is 0 or more and the first threshold value k1 or less (0≦ΔS2≦k1) Each coefficient value (A1, B1, C1, D1) is stored corresponding to the value "a1" of the weighting coefficient α.

In the example shown in FIG. 14, the storage unit 26a stores the weighting factor α when the pixel luminance difference ΔS2 is greater than the first threshold k1 and equal to or less than the first threshold k2 (k1<ΔS2≦k2). Each coefficient value (A2, B2, C2, D2) is stored corresponding to the value "a2".

In the example shown in FIG. 14, the storage unit 26a stores the weighting factor α when the pixel luminance difference ΔS2 is greater than the first threshold k2 and equal to or less than the first threshold k3 (k2<ΔS2≦k3). Each coefficient value (A3, B3, C3, D3) is stored corresponding to the value "a3".

In the example shown in FIG. 14, the storage unit 26a stores the weighting factor α when the pixel luminance difference ΔS2 is greater than the first threshold k3 and equal to or less than the first threshold k4 (k3<ΔS2≦k4). Each coefficient value (A4, B4, C4, D4) is stored corresponding to the value "a4".

In the example shown in FIG. 14, the storage unit 26a stores each coefficient value (A5, B5, C5, D5) are stored.

In addition, in the example shown in FIG. 14, the following formulas (15) and (16) hold.

k1<k2<k3<k4 (15)

a1>a2>a3>a4>a5 (16)

The averaging processor 23a compares the pixel luminance difference ΔS2 calculated by the luminance difference calculator 28a with each of predetermined first threshold values k1, k2, k3, and k4, and calculates the pixel luminance difference as shown in FIG. When ΔS2 is equal to or greater than 0 and equal to or less than the first threshold k1 (0≦ΔS2≦k1), the weighting coefficient α is set to the value “a1”, the pixel luminance difference ΔS2 is greater than the first threshold k1, and If it is equal to or less than the first threshold k2 (k1<ΔS2≦k2), the weighting coefficient α is set to the value “a2”, and the pixel luminance difference ΔS2 is greater than the first threshold k2 and equal to or less than the first threshold k3. If (k2<ΔS2≦k3), the weighting factor α is set to the value “a3”, and if the pixel luminance difference ΔS2 is greater than the first threshold k3 and equal to or smaller than the first threshold k4 (k3<ΔS2≦k4 ), the weighting factor α is set to the value "a4", and if the pixel luminance difference ΔS2 is greater than the first threshold value k4 (k4<ΔS2), the weighting factor α is set to the value "a5".

Then, the averaging processing unit 23a calculates the range of the pixel luminance difference ΔS2, which is the sum of the differences between the pixel value X _n−1 ij and the pixel value Y _n ij at each pixel set as a sample point, and the value of the weighting factor α. are associated with and stored in the storage unit 26a, the coefficients of the terms of the above formulas (2′) and (3′) corresponding to the range of the pixel luminance difference ΔS2 are read from the data table shown in FIG. 2′) and (3′) are used to calculate the pixel value _Xn .

That is, in the present embodiment, as indicated by broken lines in FIGS. 13 and 15, pixel data of a specific pixel in pixel data for one frame is set as a sample point, and n−1 Difference between the pixel value X _n−1 ij of the second pixel data included in the second image data of the n-th frame and the pixel value Y _n ij of the first pixel data included in the first image data of the n-th frame The smaller the pixel luminance difference ΔS2, in other words, the degree of matching between the pixel value X _n−1 of the previous frame and the pixel value Y _n of the next frame at the pixel of the sample point. As 1/ΔS2 increases, the value of the weighting factor α increases. As a result, when the pixel luminance difference ΔS2, which is the sum of the differences between the pixel value X _n−1 ij and the pixel value Y _n ij at each pixel set as a sample point, is small, that is, when the pixel value of the previous frame at the sample point pixel When the matching degree 1/ΔS2 between X _n−1 and the pixel value Y _n of the next frame is large, the fluctuation of the pixel value X _n of the image data of the next frame can be increased.

As described above, in the display device 1a according to the second embodiment, the averaging processing unit 23a calculates the average luminance of the pixel values _Yn of the first pixel data included in the first image data of the n-th frame, and n If the luminance difference ΔS1 between the average luminance of the pixel value Xn ₋₁ of the second pixel data included in the second image data of the first frame and the average luminance is greater than a predetermined first threshold value k, the value of the weighting factor α is Make smaller.

Further, the averaging processing unit 23a calculates the pixel value Xn _-1 of the second pixel data included in the second image data of the n-1th frame and the first image data included in the first image data of the nth frame. If the matching degree 1/ΔS2 of the pixel data with the pixel value _Yn is greater than a predetermined first threshold value k, the value of the weighting factor α is increased.

With the above configuration, it is possible to obtain an effect of suppressing flicker in image display adapted to changes in the first image data.

According to this embodiment, it is possible to obtain the display device 1a capable of obtaining the effect of suppressing flicker in image display adapted to changes in the first image data.

(Embodiment 3)
FIG. 16 is a block diagram illustrating a configuration example of a main part of a display device according to a third embodiment; 17A and 17B are diagrams illustrating an example of display mode transition of the display device according to the third embodiment. It should be noted that duplicate descriptions of components that are equivalent or identical to those of the first and second embodiments described above will be omitted.

As shown in FIG. 16, the display device 1b according to the third embodiment has the same configuration as that of the second embodiment, but as shown in FIG. In addition to the mode and the time average image display mode, the operation of each component is different because the first display holding mode is provided.

Specifically, in the first display holding mode, the image data processing unit 20b stops updating the first image data input to the image data processing unit 20b, and averages conversion processing is performed, and the second image data is output.

That is, in the present embodiment, the first display holding mode means that updating of the first image data input to the image data processing unit 20 is stopped, and averaging processing is performed using the first image data whose updating is stopped. This is a display mode in which the image data is displayed and the second image data is output.

The frame thinning processing unit 271b stops outputting the input first image data in the first display holding mode. As a result, the first image data for the last one frame acquired during the time average image display mode is held in the first memory 21 .

In addition to the information stored in the storage unit 26 in the first embodiment or the storage unit 26a in the second embodiment, the storage unit 26b stores the predetermined time T1 for maintaining the first display holding mode.

Next, operation in the first display holding mode and switching between display modes will be described. Note that switching between display modes shown in FIG. 17 is performed by the control unit 30b.

Specifically, for example, in the time average image display mode, the user operates the user input unit 9 to select "ON" of the first display hold mode, so that the control unit 30b causes the first display hold The image data processing unit 20b is controlled so as to display in the mode.

Further, for example, when the user operates the user input unit 9 to select "OFF" of the first display retention mode, or when a predetermined time T1 has elapsed after shifting to the first display retention mode, the control The unit 30b controls the image data processing unit 20b so as to perform display in the time average image display mode.

When the user input unit 9 is a hardware button, the user may switch the display mode according to the number of times the hardware button is pressed or the elapsed time. Further, when the user input unit 9 is a touch sensor, the display mode may be switched by the user according to a touch operation on an icon displayed on the display unit 10 or a predetermined gesture. The present invention is not limited by the display mode switching method by the user.

In the first display hold mode, the control section 30b outputs a first display hold operation command to the image data processing section 20b.

The frame thinning processing unit 271b stops outputting the input first image data based on the first display holding operation command.

The image data selection unit 25 selects and outputs the second image data output from the buffer memory 24 based on the first display holding operation command.

As a result, the last one frame of the second image data obtained during the time average image display mode is output, and the image is displayed in the first display hold mode.

18 is a flowchart illustrating an example of display mode switching processing of the display device according to the third embodiment; FIG.

During the time average image display mode, the control unit 30b determines whether or not the first display holding mode "ON" is selected (step S101).

When "ON" of the first display holding mode is selected (step S101; Yes), the control section 30b outputs a first display holding operation command to the image data processing section 20b, and the first display holding mode is activated. is started for a predetermined time T1 (step S102). If the first display holding mode "ON" is not selected (step S101; No), the control unit 30b repeats the process of step S101. The process of repeating the process of step S101 is hereinafter also referred to as "first display holding mode switching waiting state".

The image data processing unit 20b shifts to the first display hold mode based on the first display hold operation command (step S103). Specifically, the frame thinning processing unit 271b stops outputting the input first image data, and the image data selection unit 25 selects and outputs the second image data output from the buffer memory 24. FIG.

During the first display holding mode, the control unit 30b determines whether or not the predetermined time T1 has passed (step S104).

If the predetermined time T1 has not elapsed (step S104; No), the control unit 30b determines whether or not the first display holding mode "OFF" has been selected (step S105). If the first display holding mode "OFF" is not selected (step S105; No), the control unit 30b returns to the process of step S104.

When the predetermined time T1 has passed (step S104; Yes), or when the first display holding mode "OFF" is selected (step S105; Yes), the control unit 30b instructs the image data processing unit 20b to A time average image display operation command is output (step S106).

The image data processing unit 20b shifts to the time average image display mode based on the time average image display operation command (step S107). Specifically, the frame thinning processing unit 271b performs frame thinning processing of the input first image data, the averaging processing unit 23b performs averaging processing, and the image data selection unit 25 outputs from the buffer memory 24. The selected second image data is selected and output.

After shifting to the time average image display mode, the process returns to step S101 and shifts to the first display holding mode switching waiting state.

An image displayed on the display unit 10 at an arbitrary timing when the user selects "ON" in the first display holding mode in the time average image display mode by the display mode switching process of the display device according to the third embodiment described above. Display can be retained. As a result, the degree of recognition of information displayed at arbitrary timing can be improved.

As described above, in the display device 1b according to the third embodiment, the frame thinning processing section 271b stops outputting the first image data when the image data selection section 25 selects the second image data.

This makes it possible to improve the degree of recognition of information displayed at arbitrary timing in the time average image display mode.

According to the present embodiment, it is possible to improve the degree of recognition of information displayed at an arbitrary timing while performing image display using the second image data that suppresses flickering of the image display due to abrupt changes in the first image data. A display device 1b can be obtained.

(Embodiment 4)
FIG. 19 is a block diagram illustrating a configuration example of a main part of a display device according to a fourth embodiment; FIG. 20 is a diagram illustrating an example of display mode transition of the display device according to the fourth embodiment. It should be noted that duplicate descriptions of components that are equivalent or identical to those of the first, second, and third embodiments described above will be omitted.

As shown in FIG. 19, the display device 1c according to the fourth embodiment has the same configuration as that of the third embodiment, but as shown in FIG. Instead of the first display holding mode in which the user input unit 9 is operated to select "ON" of the first display holding mode, the second display holding mode different from the first display holding mode is provided. behaves differently. Specifically, in the present embodiment, display in the second display hold mode is triggered by the fact that the luminance difference ΔS1 calculated by the luminance difference calculator 28c is greater than a predetermined second threshold value K1.

Specifically, in addition to the information stored in the storage unit 26 in the first embodiment or the storage unit 26a in the second embodiment, the storage unit 26c stores the predetermined time T2 for maintaining the second display holding mode.

As in the second embodiment, the luminance difference calculator 28c calculates the pixel value of the first pixel data included in the first image data for one frame input from the first memory 21 using the above equation (12). The average luminance S[Yn] of _Yn and the average luminance S _{[Xn-1 of the pixel value Xn-1 of} the second pixel data included in the second image data for one frame input from the second memory 22 ] is calculated. Alternatively, the luminance difference calculator 28c calculates the difference between the pixel value X _n−1 ij and the pixel value Y _n ij at each pixel set as the sample point using the above equation (14), as in the modification of the second embodiment. A pixel luminance difference ΔS2, which is the sum of the differences, is calculated. The luminance difference calculator 28c calculates the luminance difference ΔS1 between the calculated average luminance S[Y _n ] and the average luminance S[X _n−1 ], or the pixel value X _n−1 ij and the pixel This differs from the second embodiment in that the pixel luminance difference ΔS2, which is the sum of the differences from the value Y _n ij, is output to the control unit 30c.

Next, operation in the second display holding mode and switching between display modes will be described. Note that switching between display modes shown in FIG. 20 is performed by the control unit 30c. In this embodiment, it is necessary to calculate the luminance difference ΔS1 or the pixel luminance difference ΔS2 by the luminance difference calculator 28c. For this reason, in the present embodiment, in the normal display mode, the averaging processing unit 23c performs averaging processing, and the luminance difference calculating unit 28c performs the averaging processing, and the luminance difference calculation unit 28c calculates the amount of data included in the second image data for one frame input from the second memory 22. or the sum of the difference between the pixel value X _{n - 1} ij and the pixel value Ynij at each pixel as a sample point The configuration is such that a certain pixel luminance difference ΔS2 can be calculated.

Specifically, in the present embodiment, the control unit 30c triggers display in the second display holding mode when the luminance difference ΔS1 calculated by the luminance difference calculation unit 28c is greater than a predetermined second threshold value K1. The image data processing unit 20c is controlled so as to perform.

Alternatively, in the present embodiment, the control unit 30c performs display in the second display holding mode triggered by the fact that the pixel luminance difference ΔS2 calculated by the luminance difference calculating unit 28c is greater than a predetermined second threshold value K2. The image data processing unit 20c is controlled as follows.

Further, for example, when the user operates the user input unit 9 to select "OFF" of the second display retention mode, or when a predetermined time T2 has passed after shifting to the first display retention mode, the control The unit 30c controls the image data processing unit 20c to display in the normal display mode.

The input unit (not shown) may be, for example, a touch sensor provided on the display unit 10 or hardware buttons (not shown) provided on the display device 1c. The present invention is not limited by the display mode switching method by the user.

In the second display hold mode, the control section 30c outputs a second display hold operation command to the image data processing section 20c.

The frame thinning processing unit 271c stops outputting the input first image data based on the second display holding operation command.

The image data selection unit 25 selects and outputs the first image data output from the first memory 21 based on the second display holding operation command.

As a result, the last frame of the first image data obtained during the normal display mode is output, and the image is displayed in the second display hold mode.

FIG. 21 is a flowchart illustrating an example of display mode switching processing of the display device according to the fourth embodiment.

During the normal display mode, the controller 30c determines whether or not the luminance difference ΔS1 calculated by the luminance difference calculator 28c is greater than a predetermined second threshold K1 (ΔS1>K1). Alternatively, the controller 30c determines whether or not the pixel luminance difference ΔS2 calculated by the luminance difference calculator 28c is greater than a predetermined second threshold K2 (ΔS2>K2). (Step S201).

The control unit 30c is triggered by detecting that the luminance difference ΔS1 is greater than a predetermined second threshold K1 or detecting that the pixel luminance difference ΔS2 is greater than a predetermined second threshold K2 (step S201; Yes), a second display hold operation command is output to the image data processing unit 20c, and a timer for a predetermined time T2 for maintaining the second display hold mode is started (step S202). If the luminance difference ΔS1 is equal to or less than the predetermined second threshold K1 or the pixel luminance difference ΔS2 is equal to or less than the predetermined second threshold K2 (step S201; No), the control unit 30c repeats the process of step S201. The process of repeating the process of step S201 is hereinafter also referred to as "second display holding mode switching waiting state".

The image data processing unit 20c shifts to the second display hold mode based on the second display hold operation command (step S203). Specifically, the frame thinning processing unit 271c stops outputting the input first image data, and the image data selection unit 25 selects and outputs the first image data output from the first memory 21. FIG.

During the second display holding mode, the control unit 30c determines whether or not the predetermined time T2 has passed (step S204).

If the predetermined time T2 has not elapsed (step S204; No), the control unit 30c determines whether or not the second display holding mode "OFF" has been selected (step S205). If the second display holding mode "OFF" is not selected (step S205; No), the control unit 30c returns to the process of step S204.

When the predetermined time T2 has passed (step S204; Yes), or when the second display holding mode "OFF" is selected (step S205; Yes), the control unit 30c instructs the image data processing unit 20c to A normal display operation command is output (step S206).

The image data processing unit 20c shifts to the normal display mode based on the normal display operation command (step S207). Specifically, the frame thinning processing unit 271c stops the frame thinning processing of the input first image data, and the image data selection unit 25 selects and outputs the first image data output from the first memory 21. do.

After shifting to the normal display mode, the process returns to step S201 and shifts to the second display holding mode switching waiting state.

By the display mode switching process of the display device according to the fourth embodiment described above, it is detected that the luminance difference ΔS1 is larger than the predetermined second threshold value K1 in the normal display mode, or the pixel luminance difference ΔS2 is a predetermined value. The image displayed on the display unit 10 can be held using the detection of the second threshold value K2 as a trigger. As a result, even if the first image data includes high-brightness display content such as a pop-up window with an extremely small number of frames, the degree of recognition of information included in the first image data can be improved.

As described above, in the display device 1c according to the fourth embodiment, the frame thinning processing section 271c stops outputting the first image data when the first image data is selected by the image data selection section 25. FIG.

In addition, the image data selection unit 25 selects the average luminance of the pixel value _Yn of the first pixel data included in the first image data of the n-th frame and the second image data included in the second image data of the (n-1)th frame. is greater than a predetermined second threshold value _K1 , the first image data is selected.

Alternatively, the image data selection unit 25 selects the pixel value X _n−1 ij of the second pixel data included in the second image data of the n−1th frame and the first pixel value included in the first image data of the nth frame. is greater than a _{predetermined} second threshold value K2, the first image data is selected.

According to this embodiment, the degree of recognition of information included in the first image data can be improved.

In addition to the first display holding mode in the third embodiment described above, the second display holding mode in the fourth embodiment may be provided, or in addition to the fourth display holding mode in the fourth embodiment described above. , the mode having the first display holding mode in the third embodiment may be used.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments. The content disclosed in the embodiment is merely an example, and various modifications can be made without departing from the scope of the present invention. Appropriate changes that do not deviate from the gist of the present invention naturally belong to the technical scope of the present invention.

1, 1a, 1b, 1c display device 2 display board 3 first circuit board 4 second circuit board 6 driver IC
7 timing controller 8 host IC
9 user input section 10 display section 20, 20a, 20b, 20c image data processing section 21 first memory 22 second memory 23, 23a, 23b, 23c averaging processing section 24 buffer memory 25 image data selection section 26, 26a, 26b , 26c storage units 27, 27b, 27c data input units 28a, 28c luminance difference calculation units 30, 30b, 30c control units 271, 271b, 271c frame thinning processing unit

Claims (10)

a first memory storing first image data including a plurality of first pixel data;
a second memory storing second image data including a plurality of second pixel data;
an averaging unit that averages the pixel value of the first pixel data and the pixel value of the second pixel data for each frame;
a display unit that displays an image based on the first image data or the second image data;
When the weighting factor is α and the gamma value is β, A=α ^(1/β) , B=1−α ^(1/β) , C=1−(1−α) ^{(1 /β)} and D=(1−α) ^(1/β) as coefficients;
with
The averaging processing unit
In the averaging process, a weighted average of the pixel value of the first pixel data of the nth frame and the pixel value of the second pixel data of the (n−1)th frame is obtained using a linear approximation formula for weighted averaging. do the processing,
In the weighted average process,
Y _n is the pixel value of the first pixel data of the nth frame , X _n−1 is the pixel value of the second pixel data of the n−1th frame , and the pixel of the second pixel data of the nth frame is Calculating the pixel value _{X n of} the second pixel data of the n-th frame using the sum-of-products operation formula shown in the following equation (1) when X n−1 ≧Y n is _satisfied , _and when X n−1 <Y n is satisfied, calculating the pixel value X n of the second pixel data of the n-th frame using the sum-of-products operation formula shown in the following _equation ( ₂ ) _;
pixel value of the first pixel data of the n-th frame stored in the first memory and the second pixel data after the averaging process of the n-1th frame stored in the second memory; and outputting the pixel value after the averaging process as the second pixel data of the n-th frame and writing it back to the second memory.
X _n =AX _n−1 +BY _n (1)
Xn =CXn _{- 1} +DYn ₍ 2) The averaging processing unit
Average luminance of pixel values of the first pixel data included in the first image data of the n-th frame and pixel values of the second pixel data included in the second image data of the n-1th frame 2. The display device according to claim 1 , wherein the value of said weighting factor [alpha] is reduced when the luminance difference from the average luminance is larger than a predetermined first threshold. The averaging processing unit
a degree of matching between a pixel value of the second pixel data included in the second image data of the n−1th frame and a pixel value of the first pixel data included in the first image data of the nth frame; The display device according to claim 1 , wherein the value of the weighting factor α is increased when is larger than a predetermined first threshold. a first memory storing first image data including a plurality of first pixel data;
a second memory storing second image data including a plurality of second pixel data;
an averaging unit that averages the pixel value of the first pixel data and the pixel value of the second pixel data for each frame;
a display unit that displays an image based on the first image data or the second image data;
with
The averaging processing unit
pixel value of the first pixel data of the n-th frame stored in the first memory and the second pixel data after the averaging process of the n-1th frame stored in the second memory; performing the averaging process with the pixel value, outputting the pixel value after the averaging process as the second pixel data of the n-th frame and writing it back to the second memory;
In the averaging process, data of a predetermined number of upper bits of the pixel value of the first pixel data of the nth frame and the pixel value of the second pixel data of the (n-1)th frame are used for the averaging process. and the remaining lower bits of the pixel value of the first pixel data of the nth frame as data of the number of remaining lower bits of the pixel value of the second pixel data of the nth frame after the averaging process. apply the data with the number of bits of
display device. a frame thinning processing unit that performs frame thinning processing of the first image data to be input to the first memory;
an image data selection unit that selects one of the first image data and the second image data and outputs the image data to the display unit;
further comprising
The display unit
a normal display mode for displaying an image based on the first image data;
a time average image display mode for displaying an image based on the second image data;
has
The image data selection part is
selecting and outputting the first image data based on a normal display operation command for selecting the normal display mode;
selecting and outputting the second image data based on a time average image display operation command for selecting the time average image display mode;
The display device according to any one of claims 1 to 4 . The frame thinning processing unit
The display device according to claim 5 , wherein the frame thinning process is performed when the second image data is selected by the image data selection unit. The frame thinning processing unit
The display device according to claim 5 , wherein the output of the first image data is stopped when the second image data is selected by the image data selector. The frame thinning processing unit
The display device according to claim 5 , wherein output of the first image data is stopped when the first image data is selected by the image data selection unit. The image data selection unit
Average luminance of pixel values of the first pixel data included in the first image data of the n-th frame and pixel values of the second pixel data included in the second image data of the n-1th frame 9. The display device according to claim 8 , wherein the first image data is selected when the luminance difference from the average luminance is greater than a predetermined second threshold. The image data selection unit
a degree of matching between a pixel value of the second pixel data included in the second image data of the n−1th frame and a pixel value of the first pixel data included in the first image data of the nth frame; is greater than a second predetermined threshold, selecting the first image data.

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